Original filename as keyword

Question

I've a habit of renaming files with custom names. Thing is, I like to know what the original, camera-applied filename is so I can get back to the unaltered original if needed.
LR will append the OR file numbers to a custom name on export, but what I'd like is to automatically have the OR camera filename entered as a keyword or somewhere in the EXIF data on every file I import.
Is there a way to do this?

Answer 1

John, Reid,
You are making far too easy and quick assumptions on this issue :) There are a number of reasons to want this feature.
Many pros retain the original file name out of the camera as a reference point in new titles. For instance, I rename all files using shoot information--location, subject, etc--but I add that to the Nikon DSCXXXX original title--I reference client shoot info by the range of those numbers, and I immediately file the original RAW to offline storage using a copy for editing and working db usage. And, of course, the titling feature of LR takes this possibility into account, so they must have realized that there would be good uses for retaining the original title and simply adding text to it.
My entire collection of 200,000 images is based on that procedure.
I do not know precisely why the OP wants this, but for sure it is not an unusual request. On the other hand, as long as he retains that number as part of the title he can use the 'find' function (potentially slow if you have a large db, but....that is another matter)to locate any image by the original camera number, or any other part of the title, or any date as well.
In Bridge, you can check a box to preserve the original filename in the metadata before you rename. For that matter, Bridge CS3 is faster for renaming and a lot of other operations, so the OP could take that approach if he has both apps. If there is such a function in LR, I am unaware of where it is. In any case, doing that is common practice with professionals.